Is this Keras LSTM model underfitting?
You need to include optimizer you used to make sure it is correct.
By the way, your drop-out layers are not going to do anything, so you should take them away. 

You likely don’t have test and train data in time-series because all data points are connected. It just has prediction value and ground truth of each period. 

I recommend you use the whole dataset and rotate changing hyper-parameters of LSTM to find the best model.